Allison Engine Mustangs (Walk Around 5513)
By Glen Phillips
Publisher: Squadron/Signal Publications 1998 80 Pages
PDF 35 MB
Bright blue skies and fluffy white clouds. In the distance, thick white contrails stream behind formations of heavy bombers. Above, around, and to the front, smaller contrails are etched against the sky in a gently weaving pattern. At the front of each trail, are small silvery fighters, each suddenly shedding a pair of drop tanks and pulling around in a hard diving turn. The song of the Merlin and the rattle of machine gun fire and another Luftwaffe fighter begins its long smoking descent to the fields of Germany 25,000 feet below. One more that won't get to the bombers...
Mention the P-51 Mustang to any World War II buff and that, or a similar image, is what comes lo mind. It wasn't always that way. The Mustang started life as a private venture — some might say gamble — on the part of the fledgling North American Aviation Company to build a fighter for Britain's Royal Air Force. The RAF wanted North American to license build Curtiss P-40s, however, company president James H. "Dutch" Kindelberger convinced the British Purchasing Commission that he could build a fighter that was faster, more maneuver-able, and could fly farther than the P-40 while using the same engine. It was a tall order. Using data purchased from Curtiss and NACA, the North American design and construction teams worked around the clock. Some 120 days later, the NA-73X airframe was rolled out in September of 1940. Although lacking an engine, and being rolled out on borrowed wheels, the new ship looked every inch the fighter it promised to be.
Powered by an Allison engine, the first RAF machine rolled off the assembly line in mid-April 1941. The first RAF combat mission took place in May of 1942. The Mustang started it's combat life, not as a high altitude fighter, but as a low level reconnaissance and Army Cooperation aircraft. The Allison engine simply lacked power at higher altitudes — altitudes above 20,000. The problem was not so much with the engine as it was with the simple single stage supercharger.
Through 1942 and into 1943, the Allison-powered Mustangs evolved into a potent dive bomber, reconnaissance, and ground attack aircraft. At lower altitudes, they could hold their own and then some against enemy fighters, including the Luftwaffe's vaunted h'ocke Wulf Fwl90. Almost 1600 Allison engined Mustang I. P-51, A-36, and P-51A aircraft were built. Their homes ranged from the mud and fog of an English country airfield, to the blazing sands of North Africa, to the hot and humid sub-tropics of India and Burma.
Silvery? Not these aircraft. Despite their clean lines and racing plane looks, their world was down low where they used dull greens, browns, and grays to blend in with the terrain. Often at the end of the supply line, their drab, patchy, and faded colors were streaked with fluids and exhaust stains. The early Mustang and its Allison engine was a worker. Hard, dirty, and sweat stained, this was its world. It was Cinderella — Before the ball...